This work calculates the first correction to the leading order q\={q}dilepton production rates due to shear viscosity in an expanding gas. Themodified rates are integrated over the space-time history of a viscoushydrodynamic simulation of RHIC collisions. The net result is a {\em hardening}of $q_\perp$ spectrum with the magnitude of the correction increasing withinvariant mass. We argue that a thermal description is reliable for invariantmasses less than $M_{max}\approx(2\tau_0 T_0^2)/(\eta/s)$. For reasonablevalues of the shear viscosity and thermalization time $M_{max}\approx 4.5$ GeV.Finally, the early emission from a viscous medium is compared to emission froma longitudinally free streaming plasma. Qualitative differences in $q_\perp$spectrum are seen which could be used to extract information on thethermalization time, viscosity to entropy ratio and possibly the thermalizationmechanism in heavy-ion collisions.
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